The present invention relates generally to vented fluid closures and containers and, more particularly, to a vented closure for a fluid container with a non-pouring type fluid passage when the closure is open.
Water and other non-carbonated beverages, and particularly sports drinks, are sold in individual servings in the form of deformable plastic bottles which are squeezable. Such bottles typically have caps in the form of a pull open/push close type closure, which typically provides a single fluid passage which is not vented. The lack of a vent in the closure causes the deformable container to collapse as a consumer draws a beverage from the container while drinking, due to a pressure differential that is created between the fluid and the exterior of the container, since the external pressure is higher as the exiting liquid causes the internal pressure to decrease. At some point during the drinking process, depending on the size of the container, no additional liquid can be withdrawn from the container until the pressure is equalized by stopping the drinking process and allowing air to rush in through the single fluid passage in the closure. This equalization can cause a reflux or backwash from the consumer""s mouth into the container, which tends to contaminate the fluid in the container. Because of these problems, consumers frequently equalize pressure by holding the bottle away from the mouth and squeezing the deformable bottle in a series of squirts, with pressure equalization taking place between each squirt. This procedure often results in spills of the fluid, and results in the consumer drinking less than were it easier to dispense fluid. The lack of a vent in these closures also limits the freedom of design and materials for the container due to the fact that the deformable container must be able to collapse.
Conventional fluid containers are sometimes vented, but the vent typically is part of the container itself, and not part of the closure. Vented closures intended for pouring are known, but are undesirable for use in non-pouring type closures in which fluid will not continuously pour out of the bottle when the bottle is tilted downwardly. Sports bottles are an example of a non-pouring type closure which are intended to be left open for quick drinks during an activity, and can be easily knocked over. Furthermore, most pouring-type closures require the user to hold the container with particular orientation, often with the spout oriented downwardly for pouring, and such pouring closures are not suitable for sports bottles or the like in which the user may raise the closure without regard to any particular orientation to the closure. In general, pouring type closures are not suitable for sports bottles and other deformable containers in which the liquid exits in spurts due to squeezing of the container and/or placing the user""s mouth around the closure opening to draw liquid out of the container.
Other non-pouring type closure systems have utilized a flap valve or diaphragm to regulate the equalization pressure and/or prevent liquid from leaking through vent passages for the closure. The additional components and assembly processes required to incorporate a flap valve or diaphragms or washers in a closure adds prohibitive expense and complexity to the closure. Containers designed for the application of drinking while moving are designed to allow the user to drink without tilting the head back. Such devices may use a straw to draw liquid from the bottom of an essentially rigid container and operate similar to a pouring-type container. Further, such devices may use a flap valve or other complex mechanism to vent the rigid container. Such approaches are not suitable for a standard beverage container and add prohibitive expense and complexity to the closure.
The manufacturing cost of closures used on sports drink containers and the like is critical. An increase of fractions of one cent can severely impact marketability by the closure manufacturer since consumers usually are focused on the sports beverage or supplier and are generally unwilling to pay more for the bottle and closure which contains the beverage. Likewise, it is very important that any closure should be compatible with existing bottling and assembly equipment and should be usable in connection with standard bottling and assembly processes. The types of closures proposed in the past have been incompatible with these requirements.
One objective of the present invention is to provide an improved vented fluid container closure of the non-pouring type that is adaptable to a standard beverage container.
It is another objective of the present invention to provide fluid container closures that are readily manufactured using molding and other equipment currently used for beverage container closures and which are easily adaptable to current beverage filling and processing equipment.
It is a further objective of the present invention to solve the problem of contamination of fluid while drinking due to reflux in a squeezable plastic container which dispenses liquid in squirts when held overhead in no particular orientation.
It is yet another objective of the present invention to provide improved push-pull type closures and improved flip-top rotatable type closures that allows drawing of fluid out of containers and provide new closure features adaptable to standard beverage filling and processing equipment.
It is still another objective of the present invention to provide a liquid closure that is vented to air and has vent passageways that self-seal using the surface tension of liquid in direct liquid contact with one or more vent apertures and which eliminates valves, flaps and other sealing mechanisms.
In order to achieve the foregoing objectives, the vented closures of the present invention provide non-pouring type closures with a fluid passage and one or more vent passages of predetermined dimensions and placement in an annular collar adaptable to a standard beverage container. The fluid passage and the one or more vent passages may be opened and closed by the same cap. When the cap is open and inverted to a drinking position, surface tension of the liquid will seal the one or more vent passages which are in direct contact with the liquid, and eliminate special sealing structure previously necessary for the vent passageways. The vent openings are sufficiently small size and placement relative to the main fluid exit so that the weight of the liquid which is in direct contact with the vent openings does not exert sufficient force to overcome surface tension and substantially prevents equalizing air from entering the vent passageways. The resulting pressure differential prevents liquid from exiting the bottle during equilibrium even when the closure is open and inverted.
When liquid is drawn out a main liquid passageway, as in the act of drinking due to squeezing the container and/or sucking on an open cap, sufficient additional force is applied to overcome the surface tension sealing the vent apertures, and equalizing air is drawn into the vent passage for as long as the drawing force is present. When the drawing force is removed, the surface tension of the liquid substantially reseals the vent and allows only a few drops of liquid to exit before differential pressure stops the flow.
The air entering the vent passageway is desirably separated from the flow of exiting liquid by a divider to prevent the air from becoming entrained. Several embodiments for the dividers are disclosed which are sufficiently open in configuration to allow the self-sealing action during equilibrium, and when a destabilizing force is present permits entry of air while minimizing interaction between the air entering the container and liquid exiting the container.
Certain embodiments consist of push-pull type caps that engage an annular collar. The cap is movable along the collar between open and closed positions, and when in the open position, the vent passage and fluid passage are both open. A divider which isolates the equalizing venting, air from the exiting fluid can take several forms which generally are partially open in profile such that the more open portion is opposite the main fluid passageway.
Other embodiments consist of flip-type caps of generally U-shape which rotate about a pivot base. One or more air vents formed on one side of the rotatable cap can take several forms which each provide direct liquid contact of sufficiently small size and placement to self-seal when the liquid in the container is in equilibrium with outside pressure. A divider which isolates the equalizing venting air from the main fluid flow can take several forms including a curved or serpentine path.